At this point, it is important to note that the above derivations can
be applied with little extra work to multi-dimensional optimization
problems since they do not explicitly require 1D assumptions. Thus,
they are inherently different from 1D search techniques such as
bisection, Brent's method, etc. In the following chapter, we apply the
above techniques to a specific multi-dimensional problem, conditional
density estimation which is of particular interest. However, it is not
the only place where the above work could be useful and many other
possibilities remain to be investigated (some are now closer at hand
than others).